Effects of probiotic Lactobacillus acidophilus and Candida utilis on mucus immunity indices, liver enzymes, and growth of common carp, Cyprinius carpio

The purpose of this study was to evaluate the effects of Lactobacillus acidophilus and Candida utilis probiotics on mucus immunity, growth indices and liver enzymes of common carp (Cyprinus carpio). This study was in the form of a completely randomized design with 4 treatments and 3 repetitions including: 1- basic diet, 2- basic diet + bacteria (1.23 g), 3- basic diet + yeast (0.67 g) and 4- basic ration + bacteria (0.625 g) and yeast (0.333 g) per kg of diet in 60 days. A number of 300 fish with an average weight of 12 ± 0.33 g were randomly distributed in 12 tanks (300 L) with a density of 25 fish in each tank. Based on the results, no significant difference was observed in terms of growth indices between the treatments except for the protein efficiency ratio (p>0.05). However, significant differences were found between the treatments (p<0.05) in terms of mucus immune parameters, lysozyme activity, total immunoglobulin and total protein. It was also true for AST and ALP which exhibited significant differences between the treatments (p<0.05). Based on the general results of this study, using Lactobacillus acidophilus and Candida utilis as probiotics displayed the highest enhancement on the fish immune system.